Athletes and other persons wishing to monitor their health and/or athletic performance often desire to obtain or monitor data pertaining to their physical activities, accomplishments and/or condition. In some situations, a physician, a coach or a software application may prescribe certain steps or exercises to be performed by a person under certain conditions, such as performing an exercise at or near a certain heart rate. The physician, coach or software application and/or the athlete or other person may wish to gather data regarding the performance of the exercises, the conditions under which the exercises were performed, and/or how the athlete or other person is responding to the exercises. For example, an athlete who can correlate different training or exercise techniques with improved performance metrics can become faster, stronger, or exert more force in an action, such as hitting a ball harder. Athletes, patients and anyone else associated with a physical activity can benefit from improved techniques for gathering, monitoring, correlating, analyzing, using, interpreting, and making decisions based on physical activity data, or more generally, sensor data obtained from user wearable devices.
Sensor data, including physiological data and motion data, can be obtained from battery powered user-wearable devices including sensors adapted to obtain such data. For example, a person can wear multiple user-wearable devices including sensors on various portions of their body so that such devices can obtain various different types of sensor data. However, if such devices all operate independently of one another, in a non-coordinated manner, such devices may waste limited resources and/or not obtain the data useful for monitoring metrics relevant to activities in which persons are engaged.